Apple teaches a lesson to neodymium bullies


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There has to be easier way to train apples to fly.


I taught mine to chase after poodles.

Of course, that was another problem…


Wow, that was an expensive fail!


Well, at least all the magnet parts stayed in the same block…


“Yoinks! I’m outta here!”, said apple.


I’ve started building my own motors for exotic radio telescope use. These magnets quickly teach one the value of enough wood blocks to constrain ALL axes of possible motion.


Obviously it’s the retort to this:


Early apple space flight program?


I love the demonstration that the rare earths are pyrophoric. That’s an impressive shower of sparks! (I carry a ferro-cerium rod in my backpack for the same purpose.)


Magnets were hurt in the making of this video. :sob:


God that’s just like you. Let us know when you’re ready to share Tesla’s secrets.


His big secret was that you can get people to write all sorts of heroic stuff about you after you’re dead, if you tell them you have a secret.


Oh?!? Do tell! Details, details, details!!! :smiley: :smiley: :smiley:

What about 3d-printing motor parts? There is a filament filled with iron powder, suitable for cores; using powder metal instead of stacked sheets is reportedly doable. Air cores are also used, typically for small and fast inrunners where magnetic cores would cause too high losses.

Printed cores would also allow integration of coolant channels, which could compensate for the inherent thermal instability of the material. (What about printing from something reactive, that cures into thermally stable material? What about adding a crosslinking agent with a photoinitiator - print from a thermoplastic polymer, then illuminate the layer with a UV lamp and get it set forever? What about electron-beam curing like some crosslinked polyethylene is made, again after each layer is done? Could we get an equivalent of a polyimide or other highly thermally stable material?)

We need a way to print windings… Maybe a 5-axis head with a wire dispenser, so the windings can be wound on a printed core? May be easier than getting a conductive-enough printable material…


Now tell me about Solomon. :smile:


Be water, my friend.


I really want to go camping with you.


It’s a large version of the motor in a disk drive that moves the heads, as I need to rotate a 30 inch diameter secondary mirror half a degree in about 10 milliseconds. Not quite linear motion. They have used shaker table motors until now, but they are really bad for this job, as they don’t swing in an arc.

I 3D printed the coil form at home, and the pole pieces are just steel slabs. Simple as could be! I also have an old German coil winder that does a good job of winding the 300 turns of 24 gauge wire.

I have no idea why NRAO didn’t do this in the first place. The existing gizmo is a mechanical nightmare.
Then they upgraded it…


Now, I’m a little confused here, so can someone explain how these magnets work?